The MongoMinKey class

Introdução

MongoMinKey is an special type used by the database
that compares less than all other possible BSON values. Thus, if a query is
sorted by a given field in ascending order, any document with a
MongoMinKey as its value will be returned first.

MongoMinKey has no associated fields, methods, or
constants. It is merely the "smallest" value that can be represented in the
database.

Nota:
MongoMinKey is used internally by MongoDB for
indexing and sharding. There is generally no reason to use this class in
an application.

The cursor will return the lunch document followed by the staff meeting
document. The lunch document will always be returned first, regardless of
what else is added to the collection (unless other documents are added with
MongoMinKey in their "doBy" field).